Optical in-line amplifier and wavelength-division multiplexer

Abstract

An optical in-line amplifier and a wavelength-division multiplexer suitable for a fiber-optic network that performs bi-directional transmission over a single optical fiber while using different wavelengths for each direction. By performing wavelength routing using three port devices, optical signals for each direction are separated and extracted. Subsequently, the signals are multiplexed and amplified together with a fiber amplifier. The amplified signals are once again routed to separate and extract the optical signals for each direction and to guide them in the proper direction.

What is claimed is:  
     
         1 . An optical in-line amplifier used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the optical in-line amplifier comprising: 
 a first bi-directional transmission port;    a second bi-directional transmission port;    a first thin-film filter type three-port device having a common port, a transmission port, and a reflection port, the common port being connected to the first bi-directional transmission port;    a second thin-film filter type three-port device having a common port, a transmission port, and a reflection port, the common port being connected to the second bi-directional transmission port;    a first optical amplifier for amplifying optical signals transmitted from the first bi-directional transmission port via the common port of the first thin-film filter type three-port device and the reflection port of the same three-port device; and    a second optical amplifier for amplifying optical signals transmitted from the second bi-directional transmission port via the common port of the second thin-film filter type three-port device and the reflection port of the same three-port device,    wherein the optical signal amplified by the first optical amplifier is outputted to the common port of the second thin-film filter type three-port device via the transmission port of the same, and the optical signal amplified by the second optical amplifier is outputted to the common port of the first thin-film filter type three-port device via the transmission port of the same.    
     
     
         2 . An optical in-line amplifier used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the optical in-line amplifier comprising: 
 a first wavelength-division multiplexer for extracting optical signals of a first wavelength;    a second wavelength-division multiplexer for extracting optical signals of a second wavelength;    a third wavelength-division multiplexer for combining optical signals of the first and second wavelengths;    a single optical amplifier for amplifying the optical signals of the first and second wavelengths combined by the third wavelength-division multiplexer;    a fourth wavelength-division multiplexer for separating the amplified optical signals of the first and second wavelengths and sending the optical signal of the first wavelength to the second wavelength-division multiplexer and the optical signals of the second wavelength to the first wavelength-division multiplexer.    
     
     
         3 . An optical in-line amplifier used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the optical in-line amplifier comprising: 
 a first wavelength-division multiplexer for extracting a group of optical signals of a plurality of wavelengths within a first group of wavelengths;    a second wavelength-division multiplexer for extracting a group of optical signals of a plurality of wavelengths within a second group of wavelengths;    a third wavelength-division multiplexer for combining groups of optical signals having wavelengths within the first and second groups of wavelengths;    a single optical amplifier for amplifying the optical signals of the first and second groups of wavelengths combined by the third wavelength-division multiplexer;    a fourth wavelength-division multiplexer for separating the amplified optical signals of the first and second groups of wavelengths and sending the optical signals of the first group of wavelengths to the second wavelength-division multiplexer and the optical signals of the second group of wavelengths to the first wavelength-division multiplexer.    
     
     
         4 . A wavelength-division multiplexer used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the wavelength-division multiplexer comprising: 
 first and second transmission/reception ports;    a first optical transceiver for generating optical signals of a first wavelength;    a second optical transceiver for generating optical signals of a second wavelength;    a single optical amplifier;    a single wave combining device; and    first through third wavelength-division multiplexers,    wherein the wave combining device combines optical signals received from the first and second optical transceivers; the optical amplifier amplifies the optical signals of both the first and second wavelengths together; the first wavelength-division multiplexer separates the optical signals of the first wavelength and second wavelength and transmits the signals to the first and second transmission/reception ports via the second and third wavelength-division multiplexers.    
     
     
         5 . A wavelength-division multiplexer used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the wavelength-division multiplexer comprising: 
 first and second transmission/reception ports;    a first group of optical transceivers for generating optical signals of a plurality of wavelengths within a first group of wavelengths;    a second group of optical transceivers for generating optical signals of a plurality of wavelengths within a second group of wavelengths;    a single optical amplifier;    a single wave combining device; and    first through third wavelength-division multiplexers, wherein the wave combining device combines optical signals received from the first and second optical transceivers; the optical amplifier amplifies the optical signal groups of both the first and second groups of wavelengths together; the first wavelength-division multiplexer separates the optical signal groups of the first group of wavelengths and the second group of wavelengths and transmits the optical signal groups to the first and second transmission/reception ports via the second and third wavelength-division multiplexers.    
     
     
         6 . A wavelength-division multiplexer used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the wavelength-division multiplexer comprising: 
 first and second transmission/reception ports;    a first optical transceiver for generating optical signals of a first wavelength;    a second optical transceiver for generating optical signals of a second wavelength;    a single optical amplifier;    a single wave combining device; and    first through third wavelength-division multiplexers,    wherein the wave combining device combines optical signals received from the first and second transmission/reception ports; the optical amplifier amplifies the optical signals of both the first and second wavelengths together; the first wavelength division multiplexer separates the optical signals of the first wavelength and second wavelength and transmits the signals to the first and second optical transceivers via the second and third wavelength-division multiplexers.    
     
     
         7 . A wavelength-division multiplexer used in a fiber-optic communication network performing bi-directional transmission over a single optical fiber using different wavelengths for each direction, the wavelength-division multiplexer comprising: 
 first and second transmission/reception ports;    a first group of optical transceivers for generating optical signals of a plurality of wavelengths within a first group of wavelengths;    a second group of optical transceivers for generating optical signals of a plurality of wavelengths within a second group of wavelengths;    a single optical amplifier;    a single wave combining device; and    first through third wavelength-division multiplexers,    wherein the wave combining device combines optical signals received from the first and second transmission/reception ports; the optical amplifier amplifies the optical signal groups of both the first and second groups of wavelengths together; the first wavelength-division multiplexer separates the optical signal groups of the first group of wavelengths and the second group of wavelengths and transmits the optical signal groups to the first and second optical transceivers via the second and third wavelength-division multiplexers.